Game Room

This is cumulative across all games, but you actually need to be in the game, not the title screen.

After a few minutes idle in a game, the screen goes black, and it stops counting your time.

However, depending on the game, you might be able to let it run unattended with a turbo controller. If you have Armor Battle, put LB (switch tanks) on turbo, and it'll work great. I suspect most of the 2-player Intellivision ones work the same way, because there won't be anyone to attack you.

Or, you could actually play for the alloted time.

I would advise against trying to rubberband this, as a lot of people who have tried have not been able to get it to work.

The achievement will pop immediately during the game.

This achievement is only possible with paid content. Time towards this achievement only counts while in a game, not on the title screen.

While all of the solutions here will work, the best way to get this achievement now that Game Pack 3 is out is to buy Super Breakout for 240 MSP.

All you have to do in Super Breakout is to start a ranked game and hit A once to start the first ball. After this, all you have to do is wait. The screen never blacks out using this method, but since I only have wireless controllers I personally had to press a button every 15 minutes to keep it from shutting off, but if you have a wired controller this won't be an issue. (Update: A game update was released, which now requires that you have to rubber band your controller so that the control stick is going some direction if you want the time to count).

As far as I know, time spent playing will only add to the total playtime after the game has ended, so you may want to periodically exit the game and start again every few hours in case the game freezes and you lose your progress.

Why is this method better than doing it on Adventure? Mostly because Super Breakout allows you to get 3 medals, while Adventure only allows you to get the time spender medal. Thus, it is more efficient this way if you are going for buying the least amount of games to get the most number of achievements. This method also allows you to get the "Play for one hour continuously" achievement with ease.

NOTE: If you are in fact going for all the achievements, then it should go without saying to go for the "Spend X number of hours in your arcade" achievements last, after you already have enough medals to get to level 20. By saving this for the end, you will already have many hours of playing time logged and the needed time remaining will be much less (if any), meaning less time overall spent to get all the achievements.

UPDATE: Unsure if this still works. A game update was released, and the time doesn't seem to be keeping track past 1 minute of no movement for me. Any comments regarding this would be appreciated. (Update: Think this was due to them updating requiring rubber banding, see comments below, although this method still doesn't appear to be working for me personally. I've gotten several thumbs up since discovering this no longer works for me, so I believe it still works for some people - comments below are appreciated).

This achievement requires that you play games for 8 hours. You can obviously just play games for 8 hours, but I used an alternate method for this that also gets me the gold time spender medal. The way I did this was using a turbo controller. Enter the classic mode (not ranked) of just about any game and then turn turbo on for the left trigger (the rewind button). I used a Hori X-2 for this.

This will result in the game slowly rewinding until it rewinds as far as it can, and then it will move forward half a second, rewind back, and then repeat the process again and again. I leave it on when I go to work, go to sleep, hang out with friends, whatever.

It seems to record the time properly as well, as some methods it doesn't seem to record the full time. Achievement will pop whenever you've hit the 8 hour mark.

Also, you can use this to get the gold time spender medals, if you've payed for the game.

I made this video for the Matchstick Eyes. I've found Adventure to be the easiest, but that's me. Make sure you save it every few hours to make sure the time saves. If you leave it overnight, back out first thing in the morning so you can get the hours.

I'm pretty sure that even if it glitches, you get some time credited to the achievement, but I'm not entirely sure.

EDIT: It looks like it's been patched, so you may need to keep a button on the controller pressed down by taping it or using a turbo controller. That way the console thinks you're actually there.

I did this one with Shaolin's Road, and rubber-banded my right stick at the title screen after popping in a credit on Classic Mode, and just let it run for hours on the title screen into the demo play and back over and over. ^_^

I did it on my Windows Phone (Lunar Lander, Pitfall). If you have any of the game-room titles for the phone (Lunar Lander, Pitfall, Centipede, Asteroids) the time spend there is added to game-room on the Xbox when you start it the next time.

So you can play something else on the Xbox while your phone does the grinding, you just have to tap on your Phone to start a new game (Lunar Lander every 5 min. and Pitfall every 20 min.)...;-)